The DoJ's probe, said to be aided by the Philadelphia Parking Authority, will investigate whether the taxi upstart violated federal laws when it used the Greyball tool to single out phones used by law enforcement officials to try to catch illegal activity by Uber drivers.

It is alleged that phones identified on "Greyball" were flagged to drivers as breaking Uber's terms of service and the users were assigned fake drivers when they requested a ride with the Uber app. (The drivers, of course, never showed up.)

The investigations seek to determine whether Uber's use of the tool to evade police detection should be considered a criminal act. Uber did not respond to a request for comment.

Meanwhile, Uber has shelled out $40,000 to do away with allegations that it flooded people in Washington state with text spams.

Attorney General Bob Ferguson says that his office received multiple reports of Uber sending out unsolicited text messages to customers for weeks on end, in some cases mistakenly serving them with messages intended for drivers as well. One person who complained to the state said she received up to 20 unsolicited texts from Uber.

Ferguson said that the state will drop the investigation after Uber agreed to cover the costs and fees associated with the case and took a deal banning it from sending any further unsolicited text messages to people in Washington. Uber will also provide customers who are signed on to get texts with clear opt-out instructions.

"Receiving text messages you didn't ask for – and not knowing how to stop them – frustrates consumers,” Ferguson said in announcing the settlement. "This agreement ensures that consumers control whether they receive messages from Uber." ®

Stop press: The city of Austin, in Texas, is also joining the DoJ's probe into Uber, reportedly.